Material waste sorting system and method

ABSTRACT

Exemplary embodiments include improved systems and methods for sorting and metering materials to be recycled at a material recovery facility. Systems and methods for the accurate and automated sorting and metering of recoverable materials may include a bunker with an integral conveyor adapted to meter presorted materials such that predetermined amounts of the materials may be delivered to a baler for baling and sale. Exemplary systems may include an auger screw type conveyor sized and shaped to deliver the materials to, for example, a baling system. The systems may also include a crusher for reducing the volume of the materials prior to metering from the bunker; by reducing the volume of the materials in the bunker, a baler may operate more efficiently, increasing output from the facility.

This application is a divisional and continuation of U.S. applicationSer. No. 13/567,819, filed Aug. 6, 2012, which is now U.S. Pat. No.9,586,770, which claims the benefit of U.S. Provisional Application No.61/515,842, filed Aug. 5, 2011, each of which is hereby incorporated byreference in its entirety.

BACKGROUND AND SUMMARY

The life-cycle of many to-be-recycled materials includes sorting at aMaterial Recovery Facility (MRF) and subsequent baling prior to shippingto an end recycler. This sorting and baling is done to improve theefficiency of recovery and to more accurately track amounts of materialsbeing sent to the ultimate recyclers.

When a material enters a MRF, it generally is sent along a conveyorwhere it is sorted. The sorted materials are delivered to individualcontainment areas to accumulate. When it has been determined that asufficient amount has been collected, the material is sent to a baler.Balers have materials delivered to them, often on a conveyor belt, andperform some compaction prior to forming and tying the bundled materialsinto individual bales.

Conventional sorting and baling facilities rely on two types systems fordelivering materials to the balers. The first system has a sloped floorat the bottom of a sorting containment area. The sloped floor limits thespace in the containment area, and it requires tall, expensivefacilities to get the desired capacity. The area will have a dooropening onto a conveyor, which leads to the opening of the baler. Whenit is determined that a sufficient amount of material has beencollected, the door is opened (often by an operator who is located nearthe top of the facility, which may be uncomfortably hot), and thematerial is allowed to fall to the conveyor for transport to the baler.

In the second type, the containment area has a substantially flat floor.When it has been determined that a sufficient amount of material hasbeen collected, the material is forced out toward the baler, often by abulldozer or other heavy equipment.

Both of these systems may result in considerable error and fail todeliver consistent amounts of material to the baler. The first systemrelies on eyeballing that the right amount of material has been releasedand closing the door accordingly. The second type relies on an operatorpushing the right amount of material, often requiring large machinery,out onto a conveyor. Because these systems often provide inconsistentamounts of material to the baler, the operation of the baler can bedisrupted when there is not sufficient material to make a complete bale.

These and other unmet needs of the known art may be met by the exemplarysystems and methods described herein. Exemplary embodiments include asystem for metering waste materials. One exemplary embodiment of asystem may include: a bunker adapted to receive and store wastematerials, the bunker including an exit aperture; a chute adapted tochannel waste materials into the bunker, the chute having an upper inputaperture at a sorting area and a lower output aperture adapted to allowfor transfer of sorted materials into the bunker; a conveying meanspositioned in the bunker and adapted to convey and meter a predeterminedamount of waste material out of the bunker through the exit aperture;and a conveyor positioned to receive waste material from the conveyingmeans and deliver it to a baler. Another exemplary embodiment of asystem may include: a bunker adapted to receive and store wastematerials, the bunker comprising an exit aperture; a chute adapted tochannel waste materials into the bunker, the chute having an upper inputaperture at a sorting area and a lower output aperture adapted to allowfor transfer of waste materials into the bunker; means for weighing theamount of waste material in the bunker; a conveying means in associationwith the means for weighing, the conveying means adapted to convey andmeter a predetermined amount of waste material out of the bunker throughthe exit aperture; and a conveyor positioned to receive waste materialfrom the conveying means; wherein the means for weighing is adapted tofacilitate transfer of a predetermined amount of waste material from thebunker to the conveyor. Exemplary embodiments of these systems may alsoinclude compaction means to compact (e.g., crush, densify, or otherwisecompact) the waste material entering the bunker, thus maximizing thespace in the bunker. Other exemplary embodiments may comprise variouscombinations of some or all of the aforementioned features.

Exemplary embodiments also include a method for metering and balingwaste materials. One exemplary embodiment of a method may include:sorting waste materials; depositing the sorted materials in a bunkerthat comprises an exit aperture and a conveying means adapted to conveyand meter a predetermined amount of waste material out of the bunkerthrough the exit aperture; and metering a predetermined amount of wastematerial out of the exit aperture such as for baling. The method mayfurther comprise transferring the waste material to a conveyorassociated with a baling apparatus. Moreover, the method may includeembodiments wherein the conveying means is an auger screw. Additionally,exemplary methods may include embodiments comprising the step ofcompacting the waste material prior to deposition in the bunker, and/orfurther comprising the step of weighing the waste material in the bunkerto facilitate the step of metering a predetermined amount of wastematerial out of the exit aperture.

Additional advantages of the disclosed method and systems are in thedescription which follows, and in part are understood from thedescription, or may be learned by practice of the disclosed method andsystems. For example, some embodiments may also be useful in other typesof systems or for processing other types of materials. The advantages ofthe disclosed method and systems are realized and attained by means ofthe elements and combinations particularly pointed out in the appendedclaims. It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive.

In addition to the novel features and advantages mentioned above, otherbenefits will be readily apparent from the following descriptions of thedrawings and exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an exemplary MRF.

FIG. 2 is a perspective view of an exemplary MRF.

FIG. 3 is a perspective view of an exemplary embodiment of a bunker.

FIG. 4 is a perspective view of an exemplary embodiment of a bunker.

FIG. 5 is cross-section view of an exemplary embodiment of a bunker in aMRF.

FIG. 6 is a bottom perspective view of an aspect of an exemplaryembodiment of a bunker.

FIG. 7 is a side perspective view of an aspect of an exemplaryembodiment of a bunker and associated equipment.

FIG. 8 is a side perspective view of an aspect of an exemplary bunker.

FIG. 9 is a cross-section view of an exemplary embodiment of a crusher.

FIG. 10 is a cross-section view of another exemplary embodiment of abunker comprising a compactor.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT(S)

Conventional Material Recovery Facilities (MRF) suffer frominefficiencies in the storing and baling of sorted materials. Materialssent to MRF are sorted and held until a sufficient amount of thematerial has been collected and then the material is dispensed to abaler for bundling and removal to a facility for reuse. Uniform size ofthe bales allows for more efficient transport and along with that, moreefficient use of the baler allows for increased output from thefacility. However, as described above, conventional delivery ofmaterials to the baler is subject to substantial errors and time lags.For instance, an insufficient amount of material delivered to the balercan disrupt the operation of the baler. Accordingly, exemplaryembodiments include systems and methods for increasing efficiency of thestorage, metering, and delivery of materials such as to a baler at aMRF. Exemplary embodiments may include a bunker for collecting sortedmaterials. In one example, the bunker is equipped with a conveyingmeans, wherein the conveying means is adapted to convey and meter thesorted waste out of the bunker for transport to, for example, the balingsystem and may comprise an auger screw or other conveying means such asother types of screw conveyors or rotating delivery devices, otherpushing devices, walking floors, or other suitable conveyors or meteringdevices. The conveying means may be turned on or off depending on theamount of sorted material in the respective bunker. An exemplaryembodiment of a system may include a controller in communication with aweighing means. The weighing means may determine the amount of materialin the bunker, and send the information to the controller, which mayturn the conveying means on or off depending on predetermined setamounts.

Often, materials that are sorted at the facility must be compacted forbaling. Conventional MRF merely deliver the material to the baler andhave the baler compact the material prior to baling. This can create alogjam at the baler leading to decreased output at the facility.Accordingly, disclosed embodiments describe systems that may include acrusher or other compactor for reducing the volume of the sortedmaterials prior to delivery to the baling system. In one example, thecrusher may be located in the bunker, receive sorted materials, andcompact the materials prior to collection in the bunker.

When compacting takes place in the bunker, and often in the absence ofcompacting, waste liquids fall from the sorted materials. These liquidsmay facilitate deterioration of the bunker and the machinery therein orotherwise be a nuisance. Accordingly, an exemplary embodiment of asystem may include drains associated with the bunker (e.g., in a lowersection) or as a part of an optional compactor, collecting and removingthe liquids prior to collection in the respective bunker.

FIG. 1 shows an exemplary MRF. Here the materials will be dropped onto asorting conveyor 5 running the length of the sorting area. Manyfacilities employ human sorters who then remove materials depending ontheir composition and place the materials into a chute or chutes 120. Inan exemplary embodiment, the chute opens into a holding area, termed abunker (not shown) below the conveyor. The bunker is a holding areawhere the materials are subsequently metered-from prior to, for example,baling at a baler 130. Each bunker may include an exit aperture that thematerial is metered through onto a conveyor 140, which will deliver thematerial to the baler. In this way, different materials can be deliveredto a baler along one conveyor.

FIG. 2 shows an exemplary MRF. In an exemplary embodiment, the chutes120 are positioned above the bunkers 110 with two chutes feeding eachbunker, one positioned on each side of the sorting conveyor 5. Here, oneside of the bunker is shown, with the exit apertures obscured by theoptional covers 111. When an appropriate amount of material has beendeposited in a respective bunker, the material may be metered from thebunker through the exit aperture to the conveyor 140.

Exemplary embodiments may also be used with other variations of a MRF.For example, some exemplary embodiments may be used with automaticsorting systems. For another example, some exemplary embodiments may beused with other mechanisms for allowing input to the bunker, and someexemplary embodiments may be used with different systems that receivethe output from the bunker. Other variations are possible.

FIG. 3 shows an embodiment of a bunker. In one exemplary embodiment, thebunker may be comprised of an elongate rectangular hopper with a roundedlower edge 115. The bunker has two inwardly sloping walls 112 whichserve to feed the material to a conveying means 150 at the base of thehopper. In comparison to a conventional collection area with a slopedwall for forcing out the material when a door is opened, an exemplaryembodiment of the bunker may be approximately 40% more efficient. Forexample, the bunker may hold approximately 70 cubic yards of wastematerial versus a conventional collection area that may only holdapproximately 50 cubic yards because of the significant sloped wall.Those of skill in the art will recognize that the exact shape and sizeof the bunker may be altered while still retaining the essential core ofthe inventive concept, thus alternative embodiments contemplate many3-dimensional shapes, such as, for example, a cylinder, so long as theshape is capable of providing materials to a conveying means formetering to, for example, a baler. The conveying means forces thematerial out through the exit aperture 114 on a first side 116 of thebunker. An example of the bunker may rest on a set of legs 117. In anembodiment, the legs may be adapted to include a means for weighing (notshown), which is adapted to determine the weight of the material in thebunker for use in determining when to dispense material.

FIG. 4 shows an embodiment of a bunker 110. In this example, the exitaperture of the bunker is obscured by the cover 111, which may overlaythe width of the conveyor (not shown) and serve to direct the meteredmaterial downward to the conveyor as it is metered from the bunker bythe conveying means (not shown). Additionally, the figure shows the legs117 fitted with means for weighing 160. In an embodiment, the means forweighing comprises at least one load cell adapted to determine theweight of the material in the respective bunker.

FIG. 5 shows a cross-section view of a bunker in a MRF. In anembodiment, sorted material is deposited in a chute 120 through an upperinput opening 121 which feeds into a lower output opening 122. In anexemplary embodiment, the output opening may open into a compactionmeans 170. The compaction means may reduce the volume of the materialprior to feeding the material to the bunker 110. The bunker may beshaped and sized to efficiently feed the reduced volume material to aconveying means 150. In an embodiment, the conveying means comprises anauger screw. Other types of conveying devices are possible. In thisexample, the auger screw is sized and shaped to deliver a predeterminedamount of material through the exit aperture 114 to increase theefficiency of the baling process. In an embodiment, the conveying meansmay be driven by a motor 151 (e.g., a variable frequency drive). Themotor may be positioned on the outside of the bunker as shown in thefigure, however, those with skill in the art will recognize that themotor may be positioned in any of a number of locations and stillfunction accordingly. The cover 111 can be seen over-laying the portionof the conveying means that extends out from the exit aperture and overthe conveyor 140. In this exemplary embodiment, the bunker is shownresting on a weighing means 160 for determining the weight of thematerial in the respective bunker. In an embodiment, the weighing meansmay comprise a load cell or other suitable scales or weighing apparatus.Optionally, the bunker may include a drain (not shown) for waste liquidsthat might accompany the materials into the bunker. In one example, thedrain may be located on the lower edge of the bunker.

FIG. 6 shows a view from the bottom of an exemplary bunker 110. Duringoperation of the MRF, sorted materials are dropped into the bunker;often however, the materials have unwanted liquids in or on them.Without a drain, the liquids would accumulate in the bunker and causethe deterioration of the system or otherwise be a nuisance. Thus, in anexemplary embodiment, the bunker may include a drain 180 along its lowerrounded edge 115. Here, the drain includes piping to direct the wasteliquid out from the bunker. Alternatively, the drain could be positionedin another location within the bunker, such as near the base of thechute or associated with the optional compactor (e.g., crusher,densifier, etc.) to direct unwanted liquids away from the bunker withoutallowing them to accumulate at the base of the bunker. Optionally, thepiping from the drain may include an automatic or manual shut-off valvefor stopping the flow of waste liquids from the bunker.

FIG. 7 shows an embodiment of a bunker 110. In this example, the motorfor the conveying means is shown on the outside of the bunker. Thepiping from the drain can be seen leading away from the base of thebunker. Optionally, the piping may lead to a surge tank 200 with aninternal pump. The surge tank and pump serve to pump the waste liquidsto a storage tank 210 for holding until disposal. In another embodiment,the piping may lead to another drain for disposal.

FIG. 8 shows an embodiment of a leg supporting an exemplary bunker. Asdescribed above, the conveying means may be automated to meterpredetermined amounts of material to a baling system, for example. In anembodiment, the conveying means is controlled by a controller means 162.The controller means may be any suitable controller, processor,computer, or any other suitable device adapted to control the operationof the conveying means. The controller means may be in communicationwith an optional connection point 161, and the connection point may bein communication with the means for weighing 160. Therefore, in anembodiment, the means for weighing sends a signal to the optionalconnection point, and the connection point sends a signal to thecontroller means. The controller means then turns the conveying means onor off according to predetermined criteria. In an exemplary embodiment,the predetermined criteria may include the volume or weight of materialdesired to be output from the bunker such as, for example, for forming abale.

In an embodiment, the compaction means 170 may be a crusher such asdescribed in U.S. patent application Ser. No. 13/012,277, filed on Jan.24, 2011, the content of which is hereby incorporated by reference as ifrecited fully herein. The crusher serves to reduce the volume ofmaterial prior to dropping it into the bunker. Some materials such as,for example, metal cans, plastic bottles and bags, etc. are very lowdensity and thus, the baler can operate much more efficiently if thematerial has its volume reduced prior to introduction to the baler. Inthe absence of a crusher reducing the volume of materials prior to thebaler, the baler must be used to reduce the volume of the materials,reducing the output of the MRF as a whole. For example, a conventionalbaler may require approximately 30 strokes to compact the material,whereas a baler in association with an exemplary embodiment of acompaction means may only require approximately 5 strokes (i.e., sixtimes more efficient). Moreover, containers of all sorts may containwaste liquids upon sorting, and the crusher may also serve to squeezethe unwanted liquids from the containers during the crushing process.Accordingly, the crusher may include one or more drain apertures orcomprise a grated floor to direct waste liquids form the crusher. Thecrusher may comprise a main compaction chamber with an inlet opening forreceiving sorted materials from the chute. In an embodiment of thecrusher, within the main compaction chamber is a screw assembly. Oneexample of a crusher may have screw with a flattened section tofacilitate crushing.

FIG. 9 shows a cross-section of an embodiment of an exemplary crusher170. The screw assembly may be mounted to or otherwise extend generallybetween a proximal and distal end of the compaction chamber. Exemplaryembodiments of the crusher include an electric motor to turn the screwassembly. In an exemplary embodiment, the screw assembly comprises ascrew with an increasing diameter as it drives the material from one endto the other. The increasing diameter serves to drive the materialoutward to a wall of the crusher, pinching the material between thescrew and the wall. Once the diameter of the screw reaches its largestdiameter, it includes a section having a uniform diameter (i.e., aflattened section). In one exemplary embodiment, this section maycomprise substantially half of the total length of the screw. Theextended section of enlarged diameter keeps the materials in a reducedvolume space to further crush the materials.

The walls of the compaction chamber are fabricated from materials thatare strong enough to withstand the force exerted by the materials thatare compacted or compressed by the screw assembly during operation ofthe crusher. In an exemplary embodiment, the compaction chamber may besubstantially cylindrical in geometry, with at least one opening at thedistal end of the compaction chamber that allows the compressed orcompacted material to exit. However, in other embodiments, the inletchamber may be any number of geometries and positions that allowmaterial to enter the compaction chamber.

One or more flow bars may be situated within at least a portion of theinterior of the compaction chamber. The one or more flow bars facilitatethe flow of material being compacted within the compaction chamberduring use of the crusher.

Alternatively, the crusher may be adapted to meter predetermined amountsof reduced volume materials. Accordingly, exemplary embodiments of thescrew assembly may include a metering member, such as a metering bar ormetering tube along at least a portion of the length thereof. In someembodiments, the metering member may be integral with at least a portionof the screw assembly. However, in other embodiments, the meteringmember may be removably attached to the screw assembly.

FIG. 10 shows another exemplary embodiment of a bunker that includes adifferent type of compactor. In this example, the compactor 190comprises a compression screw that is adapted to densify materials suchas plastic bags or other flat plastic sheets. Densification of thesematerials allows for much more efficient use of the bunker and, forexample, a subsequent baling system.

The terms “a” and “an” and “the” and similar references used in thecontext of describing the disclosed embodiments (especially in thecontext of the following claims) are to be construed to cover both thesingular and the plural, unless otherwise indicated herein or clearlycontradicted by context.

Recitation of ranges of values herein is merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range. Unless otherwise indicated herein, eachindividual value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein isintended merely to better illuminate the disclosed embodiments and doesnot pose a limitation on the scope of the disclosed embodiments unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element to be essential to the practice ofthe disclosed embodiments or any variants thereof.

Groupings of alternative elements or embodiments disclosed herein arenot to be construed as limitations. Each group member may be referred toand claimed individually or in any combination with other members of thegroup or other elements found herein. It is anticipated that one or moremembers of a group may be included in, or deleted from, a group forreasons of convenience and/or patentability.

Exemplary embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention(s).Of course, variations on the disclosed embodiments will become apparentto those of ordinary skill in the art upon reading the foregoingdescription. The inventors expect skilled artisans to employ suchvariations as appropriate, and the inventors intend for the invention(s)to be practiced otherwise than as specifically described herein.Accordingly, this disclosure includes all modifications and equivalentsof the subject matter recited in the claims appended hereto as permittedby applicable law. Moreover, any combination of the above describedelements in all possible variations thereof is encompassed by thedisclosed embodiments unless otherwise indicated herein or otherwiseclearly contradicted by context.

Having shown and described exemplary embodiments of the invention, thoseskilled in the art will realize that many variations and modificationsmay be made to affect the described invention and still be within thescope of the claimed invention. Additionally, many of the elementsindicated above may be altered or replaced by different elements whichwill provide the same result and fall within the spirit of the claimedinvention. It is the intention, therefore, to limit the invention onlyas indicated by the scope of the claims.

What is claimed is:
 1. A system for metering sorted waste materialscomprising: a bunker adapted to receive and store waste materials, thebunker comprising an exit aperture; a chute adapted to channel wastematerials into the bunker, the chute having an upper input aperture at asorting area and a lower output aperture adapted to allow for transferof waste materials into the bunker; means for weighing an amount ofwaste material in the bunker; a conveying means in association with themeans for weighing, the conveying means adapted to convey and meter apredetermined amount of waste material out of the bunker through theexit aperture; a controller means for controlling an operation of theconveying means such that the means for weighing the amount of wastematerial in the bunker is adapted to send a signal to the controllermeans to activate the conveying means, wherein the conveying meansconfigured to be turned on when the predetermined amount of wastematerial has been deposited in the bunker to convey and meter thepredetermined amount of waste material out of the bunker, and theconveying means configured to be turned off when the predeterminedamount of waste material has been conveyed and metered out of thebunker; and a conveyor positioned to receive waste material from theconveying means; wherein the means for weighing is adapted to facilitatetransfer of a predetermined amount of waste material from the bunker tothe conveyor.
 2. The system of claim 1 wherein the means for weighingcomprises at least one load cell.
 3. The system of claim 1 wherein saidcontroller means adapted to control the transfer of waste material fromthe bunker to the conveyor.
 4. The system of claim 1 wherein theconveying means comprises an auger screw.
 5. The system of claim 1further comprising: a drain in the bunker adapted to drain liquid fromthe bunker; and a tank in fluid communication with the drain and adaptedto collect liquid drained from the bunker.
 6. The system of claim 1wherein the bunker is comprised of an elongate rectangular hopper with alower edge defining a rounded shape.
 7. The system of claim 1 furthercomprising a compaction means in association with the lower outputaperture of the chute for reducing a volume of waste materials prior todeposition in the bunker, the compaction means adapted to receive wastematerials from the chute and deliver the reduced volume waste materialto the bunker.
 8. The system of claim 7 wherein the compaction means isadapted to crush bottles.
 9. The system of claim 7 wherein thecompaction means is adapted to densify flat plastic sheets.
 10. Thesystem of claim 1 wherein the bunker is configured to hold more than 50cubic yards of the waste material.
 11. The system of claim 1 where thebunker is configured to hold approximately 70 cubic yards of the wastematerial.
 12. A system for metering sorted waste materials comprising: abunker adapted to receive and store waste materials, the bunkercomprising an exit aperture; a weighing system adapted to weigh anamount of waste material in the bunker; a conveyor in association withthe weighing system, the conveyor adapted to convey and meter apredetermined amount of waste material out of the bunker through theexit aperture; and a controller adapted to control an operation of theconveyor such that the weighing system is adapted to send a signal tothe controller to activate the conveyor, wherein the conveyor configuredto be turned on when the predetermined amount of waste material has beendeposited in the bunker to convey and meter the predetermined amount ofwaste material out of the bunker, and the conveyor configured to beturned off when the predetermined amount of waste material has beenconveyed and metered out of the bunker, and wherein the weighing systemis adapted to facilitate transfer of a predetermined amount of wastematerial from the bunker.
 13. The system of claim 12 wherein theweighing system comprises at least one load cell.
 14. The system ofclaim 12 wherein said controller adapted to control the transfer ofwaste material from the bunker.
 15. The system of claim 12 wherein theconveyor comprises an auger screw.
 16. The system of claim 12 furthercomprising: a drain in the bunker adapted to drain liquid from thebunker; and a tank in fluid communication with the drain and adapted tocollect liquid drained from the bunker.
 17. The system of claim 12wherein the bunker is comprised of an elongate rectangular hopper with alower edge defining a rounded shape.
 18. The system of claim 12 furthercomprising a compactor adapted to reduce a volume of waste materialsprior to deposition in the bunker, the compactor adapted to receivewaste materials and deliver the reduced volume waste materials to thebunker.
 19. The system of claim 18 wherein the compactor is adapted tocrush bottles.
 20. The system of claim 18 wherein the compactor isadapted to densify flat plastic sheets.
 21. The system of claim 12wherein the bunker is configured to hold more than 50 cubic yards of thewaste material.
 22. The system of claim 12 where the bunker isconfigured to hold approximately 70 cubic yards of the waste material.